Various methods of providing an operation input to an information processing device by a user have been proposed. One of the methods uses a touch sensor capable of detecting a position of an object (such as a finger of the user or a stylus) on a detection surface (see, for example, Patent Literature 1). By using the touch sensor, the user may realize the operation input to the information processing device by performing actions of, for example, placing a finger on the detection surface or moving the finger on the detection surface.
In this case, the information processing device receives the position of the object or a moving direction of the object on the detection surface as the operation input by the user. The position and the moving direction of the object are acquired as a position and a direction with respect to the touch sensor itself. In other words, the position of the object is evaluated as an absolute position in the detection surface of the touch sensor, and the moving direction of the object is evaluated as an inclination with respect to a reference axis set in the detection surface of the touch sensor. Therefore, the user needs to provide the operation input at such a position that the detection surface comes in front of the user while, for example, confirming the position and the direction of the detection surface of the touch sensor with his/her eyes.